manufactured sand for a low carbon era - kayasand
TRANSCRIPT
Manufactured Sand For a Low Carbon Era
Martins Pilegis, Diane Gardner, Robert Lark Cardiff University
8th International Conference: Concrete in the Low Carbon Era
Dundee, UK, 9-11 July 2012
Contents Introduction Aims Sand manufacturing process Experimental methods and materials
Materials Characterisation tests Concrete mixes
Results Aggregate test results Concrete test results
Conclusions
Introduction
Background to project – WAG document: Crushed Rock Sand In South Wales, A Reconnaissance Survey, 2000.
Current practice in UK Blend crusher dust with natural sand.
Excess of sub-63 micron particles in dust Flaky and very angular Lack of 0.3 to 1 mm particles
Aims
Replace natural sand and sand blends in concrete with 100% manufactured sand
Investigate fine aggregate test applicability to manufactured sands
Sand Manufacturing process
Integrated in the quarry crusher system Dry process – the product is not washed Water added to the final product to avoid segregation (3%) “Skimmer” particles added back in the produced sand, therefore creating
different gradings (-A,-B,-C,-D) with different sub 63 micron content and increasing yield
Ver$calSha+ImpactCrusher
Feed0‐8mm
SandSand
Filler=par$cles<63μm
Materials CEM I 52.5 N Crushed limestone 4/20 mm (CA) Sea dredged natural sand control (N) Crusher dusts (..-FEED) Manufactured sands from crusher dusts with at least
4 gradings for each quarry Basalt (B) Granite (G) Limestone (L) Sandstone (Gritstone) (S)
Mid range plasticizer WRDA 90
Characterisation tests
Air Entrainment Fresh
Concrete
Hardened Concrete
Slump
Observations from mixing (finishability, ease of placement)
Plastic Density
Compressive strength – 1 day – 7 days – 28 days
Flexural strength – 28 days
Fine Aggregate
Water absorption (BS EN 1097-6)
Particle size distribution (BS EN 933-1)
New Zealand Flow Cone (NZS 3111-1986)
Methylene Blue Value (BS EN 933-9)
GMBV (Grace Rapid Clay test)
Sand Equivalent (BS EN 933-8 )
Concrete mixes Two stages
Stage 1: without plasticizer, aiming for S2 slump, fixed w/c ratio for particular quarry sands which provides S2 slump.
Stage 2: Varying plasticizer dosage to achieve S2 slump, fixed w/c ratio at 0.55 for all sands.
Accounted for absorption capacity and water content of aggregates and admixtures
Cement FA CA Water
350 753 1040 varies
Cement FA CA Water Plas$cizer
350 753 1040 193 varies
Results – Fine aggregate tests CrusherdustFeed(0‐4) Manufacturedsand(0‐4) Seadredgedsand(0‐4)
Results – Particle Size Distribution
0
20
40
60
80
100
0.01 0.1 1 10
Percen
tagepassing
,%
SieveSize,mm
Sandstonesandgrading
S‐FEED
S‐A
S‐B
S‐C
S‐D
0102030405060708090
100
0.01 0.1 1 10
Percen
tpa
ssing,%
SieveSize,mm
GranitesandgradingG‐FEED
G‐A
G‐B
G‐C
G‐D
G‐E
0102030405060708090
100
0.01 0.1 1 10
Percen
tpa
ssing,%
SieveSize,mm
Limestonesandgrading
L‐FEED
L‐A
L‐B
L‐C
L‐D
0
20
40
60
80
100
0.01 0.1 1 10
Percen
tpa
ssing,%
SieveSize,mm
Basaltsandgrading
B‐FEED
B‐A
B‐B
B‐C
B‐D
N
Results – New Zealand Flow Cone Simple indirect test indicating shape, grading and surface
texture
G-A
G-B G-C
G-D
G-E
B-A
B-B B-C
B-D
B-FEED
G-FEED
L-A
L-B L-C L-D
S-A S-B
S-C S-D
L-FEED
S-FEED
Control Natural sand
18.0
20.0
22.0
24.0
26.0
28.0
30.0
32.0
34.0
36.0
38.0
36% 41% 46%
FLO
W T
IME
, s
VOIDS, %
Granite Sand
Basalt sand
NZS 3121 specification envelope
Limestone sand
Sanstone sand
Results – MBV, GMBV, SE
0
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
N
G‐FEED
G‐A
G‐B
G‐C
G‐D
G‐E
B‐FEED
B‐A
B‐B
B‐C
B‐D
L‐FEED
L‐A
L‐B
L‐C
L‐D
S‐FEED
S‐A
S‐B
S‐C
S‐D
Samples
Sand
Equ
ivalen
t
Methylene
BlueVa
lue,g/gofsan
d
MethyleneBlueValue
GraceMethyleneBlueValueSandEquivalentValue
Naturalsand
Granite Basalt Limestone
Sandstone
Results – MBV, GMBV
Comparing two methods for MBV testing
y=1.1618x+0.0741R²=0.98991
0
1
2
3
4
5
6
7
0 1 2 3 4 5 6
GMBV
,g/gofsan
d(0‐2mmfrac$on
)
MBV,g/gofsand(0‐2mmfrac$on)
MBVversusGMBV
Results-Concrete, Stage 1
40
50
60
70
80
90
100
110
120
130
0 1 2 3 4 5 6 7 8 9 10
Slum
p,m
m
%sub‐63micronpar$clesofFA
SlumpagainstpercentageoffinesofFA
Granitesandsw/c0.58
Basaltsandsw/c0.67
Sanstonesandsw/c0.67
Limestonesandsw/c0.55
0
20
40
60
80
100
120
140
0
10
20
30
40
50
60
70
N
slum G‐A
G‐B
G‐C
G‐D
G‐E
B‐A
B‐B
B‐C
B‐D
L‐A
L‐B
L‐C
L‐D
S‐A
S‐B
S‐C
S‐D
Slum
p,m
m
Compressive,fl
exuralstren
gth,N/m
m2
Concretemixes
Compressive,flexuralstrengthandslump
1daycompressivestrength
7daycompressivestrength
28daycompressivestrength28dayflexuralstrength
Slump,mm
Granitew/c0.58 Basaltw/c0.67 Limestonew/c0.55 Sandstonew/c0.67Naturalsandw/c0.48
Results – Concrete, Stage 2
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
N G‐A G‐B G‐C G‐D G‐E B‐A B‐B B‐C B‐D L‐A L‐B L‐C L‐D
Slum
p,m
m
Compressive,fl
exuralstren
gthN/m
m2
Compressive,flexuralstrengthandslumpforw/c0.55
1daycompressivestrength
7daycompressivestrength
28daycompressivestrength
28dayflexuralstrength
Slump,mm
Granite Basalt LimestoneNaturalsand
Conclusions It has been demonstrated that viable concretes can be
produced using 100% manufactured sands Good strength and workability can be achieved
regardless of rock mineralogy by appropriate manipulation of w/c ratio and particle size distribution.
Caution must be exercised when using manufactured sands which contain clays
MBV tests are good indicators of the presence of clays
Sustainability and environmental benefits
Thank you for your attention! Any questions?
Acknowledgements: Aggregate Levy Fund for Wales, Kayasand, Kemco, Grace Construction Products, Cemex and Aggregate Industries.